Polymer Composition for an Electronic Device

ABSTRACT

A polymer composition is provided. The polymer composition comprises a liquid crystalline, an electrically conductive filler, and a mineral filler. The polymer composition exhibits a surface resistivity of from about 1×1012 ohms to about 1×1018 ohms as determined in accordance with ASTM D257-14.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims filing benefit of U.S. Provisional PatentApplication Ser. No. 62/981,681 having a filing date of Feb. 26, 2020and U.S. Provisional Patent Application Ser. No. 63/057,349 having afiling date of Jul. 28, 2020, which are incorporated herein by referencein their entirety.

BACKGROUND OF THE INVENTION

Molded interconnect devices (“MIDs”) are three-dimensionalelectromechanical parts that typically include plastic components andelectronic circuit traces. A plastic substrate or housing is created andelectrical circuits and devices are plated, layered or implanted uponthe plastic substrate. MIDs typically have fewer parts thanconventionally produced devices, which results in space and weightsavings. Current processes for manufacturing MIDs include two-shotmolding and laser direct structuring. Laser direct structuring, forinstance, involves the steps of injection molding, laser activation ofthe plastic material, and then metallization. The laser etches a wiringpattern onto the part and prepares it for metallization. Despite thebenefits of such devices, there is still a need for electronics packagesthat can be used in smaller spaces and that can operate at higherspeeds, while simultaneously using less power and being relativelyinexpensive to manufacture. One technique that has been developed tohelp solve these problems is known as “Application Specific ElectronicsPackaging (“ASEP”). Such packaging systems enable the manufacture ofproducts using reel-to-reel (continuous flow) manufacturing processes byrelying upon the use of a plated plastic substrate that is molded onto asingulated carrier portion. Unfortunately, one of the limitations ofthese systems is that the polymeric materials used for the plasticsubstrate are not easily plated with conductive circuit traces and alsodo not typically possess the desired degree of heat resistance andmechanical strength.

As such, a need currently exists for an improved polymer compositionthat can be used in a substrate of a packaged electronic device.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a polymercomposition is disclosed that comprises a liquid crystalline polymer, anelectrically conductive filler, and a mineral filler. The polymercomposition exhibits a surface resistivity of from about 1×10¹² ohms toabout 1×10¹⁸ ohms as determined in accordance with ASTM D257-14.

Other features and aspects of the present invention are set forth ingreater detail below.

BRIEF DESCRIPTION OF THE FIGURES

A full and enabling disclosure of the present invention, including thebest mode thereof to one skilled in the art, is set forth moreparticularly in the remainder of the specification, including referenceto the accompanying figures, in which:

FIG. 1 is a flow diagram of one embodiment of a manufacturing processthat may be employed to form the electronic device of the presentinvention;

FIG. 2 is a perspective view of the manufacturing process shown in FIG.1 in which a substrate is shown at various stages on a carrier duringformation of the electronic device;

FIG. 3 is a perspective view of the electronic device shown in FIG. 2after separation from the carrier;

FIG. 4 is a perspective view of one embodiment of a reel-to-reel carrierthat may be used in the manufacturing process shown in FIG. 1;

FIG. 5 is a schematic view of one embodiment for forming circuit traceson a substrate;

FIG. 6 is a flow diagram that shows additional steps that can beemployed in the manufacturing process of FIG. 1;

FIG. 7 is a perspective view of one embodiment of the electronic deviceof the present invention in the form of an automotive light; and

FIG. 8 is an exploded perspective view of the electronic device shown inFIG. 7.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that thepresent discussion is a description of exemplary embodiments only, andis not intended as limiting the broader aspects of the presentinvention.

Generally speaking, the present invention is directed to a polymercomposition that can be used in an electronic device, such as a printedcircuit board, flex circuit, connector, thermal management feature, EMIshielding, high current conductor, RFID apparatus, antenna, wirelesspower device, sensor, MEMS apparatus, LED device, microprocessor, memorydevice, ASIC, passive device, impedance control device,electro-mechanical apparatus, or a combination thereof. Notably, thepolymer composition contains a liquid crystalline polymer, anelectrically conductive filler, and a mineral filler in an amount suchthat the resulting surface resistivity is within a specific range, suchas from about 1×10¹² ohms to about 1×10¹⁶ ohms, in some embodiments fromabout 1×10¹³ ohms to about 1×10¹⁶ ohms, in some embodiments from about1×10¹⁴ ohms to about 1×10¹⁷ ohms, and in some embodiments, from about1×10¹⁵ ohms to about 1×10¹⁷ ohms, such as determined in accordance withIEC 60093. Likewise, the composition may also exhibit a volumeresistivity of from about 1×10¹⁰ ohm-m to about 1×10¹⁶ ohm-m, in someembodiments from about 1×10¹¹ ohm-m to about 1×10¹⁶ ohm-m, in someembodiments from about 1×10¹² ohm-m to about 1×10¹⁵ ohm-m, and in someembodiments, from about 1×10¹³ ohm-m to about 1×10¹⁵ ohm-m, such asdetermined in accordance with ASTM D257-14 (technically equivalent toIEC 62631-3-1). In this manner, the polymer composition can be generallyantistatic in nature such that a substantial amount of electricalcurrent does not flow therethrough. While being generally antistatic,the resulting polymer composition may nevertheless allow some degree ofelectrostatic dissipation to facilitate plating and deposition ofconductive traces thereon.

Conventionally, it was believed that compositions having suchresistivity values would also not possess good mechanical properties.Contrary to conventional thought, however, the composition of thepresent invention has been found to possess excellent strengthproperties. For example, the composition may exhibit a Charpy unnotchedand/or notched impact strength of about 2 kJ/m², in some embodimentsfrom about 4 to about 40 kJ/m², and in some embodiments, from about 6 toabout 30 kJ/m², measured at 23° C. according to ISO Test No. 179-1:2010.The composition may also exhibit a tensile strength of from about 20 toabout 500 MPa, in some embodiments from about 50 to about 400 MPa, andin some embodiments, from about 60 to about 350 MPa; tensile breakstrain of about 0.5% or more, in some embodiments from about 0.8% toabout 15%, and in some embodiments, from about 1% to about 10%; and/ortensile modulus of from about 5,000 MPa to about 30,000 MPa, in someembodiments from about 7,000 MPa to about 25,000 MPa, and in someembodiments, from about 10,000 MPa to about 20,000 MPa. The tensileproperties may be determined in accordance with ISO Test No. 527:2019 at23° C. The composition may also exhibit a flexural strength of fromabout 40 to about 500 MPa, in some embodiments from about 50 to about400 MPa, and in some embodiments, from about 100 to about 350 MPa;flexural break strain of about 0.5% or more, in some embodiments fromabout 0.8% to about 15%, and in some embodiments, from about 1% to about10%; and/or flexural modulus of about 7,000 MPa or more, in someembodiments from about 9,000 MPa or more, in some embodiments, fromabout 10,000 MPa to about 30,000 MPa, and in some embodiments, fromabout 12,000 MPa to about 25,000 MPa. The flexural properties may bedetermined in accordance with ISO Test No. 178:2019 at 23° C. Thecomposition may also exhibit a deflection temperature under load (DTUL)of about 180° C. or more, and in some embodiments, from about 190° C. toabout 280° C., as measured according to ASTM D648-07 (technicallyequivalent to ISO Test No. 75-2:2013) at a specified load of 1.8 MPa.

The polymer composition may also exhibit a high dielectric constant ofabout 4 or more, in some embodiments about 5 or more, in someembodiments about 6 or more, in some embodiments from about 8 to about30, in some embodiments from about 10 to about 25, and in someembodiments, from about 12 to about 24, as determined by the split postresonator method at a frequency of 2 GHz. Such a high dielectricconstant can facilitate the ability to form a thin substrate and alsoallow multiple conductive elements (e.g., antennae) to be employed thatoperate simultaneously with only a minimal level of electricalinterference. The dissipation factor, a measure of the loss rate ofenergy, may also be relatively low, such as about 0.3 or less, in someembodiments about 0.2 or less, in some embodiments about 0.1 or less, insome embodiments about 0.06 or less, in some embodiments about 0.04 orless, and in some embodiments, from about 0.001 to about 0.03, asdetermined by the split post resonator method at a frequency of 2 GHz.The present inventor has also discovered that the dielectric constantand dissipation factor can be maintained within the ranges noted aboveeven when exposed to various temperatures, such as a temperature of fromabout −30° C. to about 100° C. For example, when subjected to a heatcycle test as described herein, the ratio of the dielectric constantafter heat cycling to the initial dielectric constant may be about 0.8or more, in some embodiments about 0.9 or more, and in some embodiments,from about 0.95 to about 1.1. Likewise, the ratio of the dissipationfactor after being exposed to the high temperature to the initialdissipation factor may be about 1.3 or less, in some embodiments about1.2 or less, in some embodiments about 1.1 or less, in some embodimentsabout 1.0 or less, in some embodiments about 0.95 or less, in someembodiments from about 0.1 to about 0.95, and in some embodiments, fromabout 0.2 to about 0.9. The change in dissipation factor (i.e., theinitial dissipation factor−the dissipation factor after heat cycling)may also range from about −0.1 to about 0.1, in some embodiments fromabout −0.05 to about 0.01, and in some embodiments, from about −0.001 to0.

Various embodiments of the present invention will now be described inmore detail.

I. Polymer Composition

A. Polymer Matrix

The polymer matrix typically contains one or more liquid crystallinepolymers, generally in an amount of from about 30 wt. % to about 80 wt.%, in some embodiments from about 40 wt. % to about 75 wt. %, and insome embodiments, from about 50 wt. % to about 70 wt. % of the polymercomposition. Such polymers generally have a high degree of crystallinitythat enables them to effectively fill the small spaces of a mold. Liquidcrystalline polymers are generally classified as “thermotropic” to theextent that they can possess a rod-like structure and exhibit acrystalline behavior in their molten state (e.g., thermotropic nematicstate). Such polymers may be formed from one or more types of repeatingunits as is known in the art. A liquid crystalline polymer may, forexample, contain one or more aromatic ester repeating units generallyrepresented by the following Formula (I):

wherein,

ring B is a substituted or unsubstituted 6-membered aryl group (e.g.,1,4-phenylene or 1,3-phenylene), a substituted or unsubstituted6-membered aryl group fused to a substituted or unsubstituted 5- or6-membered aryl group (e.g., 2,6-naphthalene), or a substituted orunsubstituted 6-membered aryl group linked to a substituted orunsubstituted 5- or 6-membered aryl group (e.g., 4,4-biphenylene); and

Y₁ and Y₂ are independently O, C(O), NH, C(O)HN, or NHC(O).

Typically, at least one of Y₁ and Y₂ are C(O). Examples of such aromaticester repeating units may include, for instance, aromatic dicarboxylicrepeating units (Y₁ and Y₂ in Formula I are C(O)), aromatichydroxycarboxylic repeating units (Y₁ is O and Y₂ is C(O) in Formula I),as well as various combinations thereof.

Aromatic hydroxycarboxylic repeating units, for instance, may beemployed that are derived from aromatic hydroxycarboxylic acids, suchas, 4-hydroxybenzoic acid; 4-hydroxy-4′-biphenylcarboxylic acid;2-hydroxy-6-naphthoic acid; 2-hydroxy-5-naphthoic acid;3-hydroxy-2-naphthoic acid; 2-hydroxy-3-naphthoic acid;4′-hydroxyphenyl-4-benzoic acid; 3′-hydroxyphenyl-4-benzoic acid;4′-hydroxyphenyl-3-benzoic acid, etc., as well as alkyl, alkoxy, aryland halogen substituents thereof, and combination thereof. Particularlysuitable aromatic hydroxycarboxylic acids are 4-hydroxybenzoic acid(“HBA”) and 6-hydroxy-2-naphthoic acid (“HNA”). When employed, repeatingunits derived from hydroxycarboxylic acids (e.g., HBA and/or HNA)typically constitute about 40 mol. % or more, in some embodiments about45 mol. % or more, and in some embodiments, from about 50 mol. % to 100mol. % of the polymer. In one embodiment, for example, repeating unitsderived from HBA may constitute from about 30 mol. % to about 90 mol. %of the polymer, in some embodiments from about 40 mol. % to about 85mol. % of the polymer, and in some embodiments, from about 50 mol. % toabout 80 mol. % of the polymer. Repeating units derived from HNA maylikewise constitute from about 1 mol. % to about 30 mol. % of thepolymer, in some embodiments from about 2 mol. % to about 25 mol. % ofthe polymer, and in some embodiments, from about 3 mol. % to about 15mol. % of the polymer.

Aromatic dicarboxylic repeating units may also be employed that arederived from aromatic dicarboxylic acids, such as terephthalic acid,isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenylether-4,4′-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid,2,7-naphthalenedicarboxylic acid, 4,4′-dicarboxybiphenyl,bis(4-carboxyphenyl)ether, bis(4-carboxyphenyl)butane,bis(4-carboxyphenyl)ethane, bis(3-carboxyphenyl)ether,bis(3-carboxyphenyl)ethane, etc., as well as alkyl, alkoxy, aryl andhalogen substituents thereof, and combinations thereof. Particularlysuitable aromatic dicarboxylic acids may include, for instance,terephthalic acid (“TA”), isophthalic acid (“IA”), and2,6-naphthalenedicarboxylic acid (“NDA”). When employed, repeating unitsderived from aromatic dicarboxylic acids (e.g., IA, TA, and/or NDA)typically constitute from about 1 mol. % to about 50 mol. %, in someembodiments from about 2 mol. % to about 40 mol. %, and in someembodiments, from about 5 mol. % to about 30% of the polymer.

Other repeating units may also be employed in the polymer. In certainembodiments, for instance, repeating units may be employed that arederived from aromatic diols, such as hydroquinone, resorcinol,2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,1,6-dihydroxynaphthalene, 4,4′-dihydroxybiphenyl (or 4,4′-biphenol),3,3′-dihydroxybiphenyl, 3,4′-dihydroxybiphenyl, 4,4′-dihydroxybiphenylether, bis(4-hydroxyphenyl)ethane, etc., as well as alkyl, alkoxy, aryland halogen substituents thereof, and combinations thereof. Particularlysuitable aromatic diols may include, for instance, hydroquinone (“HQ”)and 4,4′-biphenol (“BP”). When employed, repeating units derived fromaromatic diols (e.g., HQ and/or BP) typically constitute from about 1mol. % to about 30 mol. %, in some embodiments from about 2 mol. % toabout 25 mol. %, and in some embodiments, from about 5 mol. % to about20% of the polymer. Repeating units may also be employed, such as thosederived from aromatic amides (e.g., acetaminophen (“APAP”)) and/oraromatic amines (e.g., 4-aminophenol (“AP”), 3-aminophenol,1,4-phenylenediamine, 1,3-phenylenediamine, etc.). When employed,repeating units derived from aromatic amides (e.g., APAP) and/oraromatic amines (e.g., AP) typically constitute from about 0.1 mol. % toabout 20 mol. %, in some embodiments from about 0.5 mol. % to about 15mol. %, and in some embodiments, from about 1 mol. % to about 10% of thepolymer. It should also be understood that various other monomericrepeating units may be incorporated into the polymer. For instance, incertain embodiments, the polymer may contain one or more repeating unitsderived from non-aromatic monomers, such as aliphatic or cycloaliphatichydroxycarboxylic acids, dicarboxylic acids, diols, amides, amines, etc.Of course, in other embodiments, the polymer may be “wholly aromatic” inthat it lacks repeating units derived from non-aromatic (e.g., aliphaticor cycloaliphatic) monomers.

Although not necessarily required, the liquid crystalline polymer may bea “low naphthenic” polymer to the extent that it contains a relativelylow content of repeating units derived from naphthenic hydroxycarboxylicacids and naphthenic dicarboxylic acids, such asnaphthalene-2,6-dicarboxylic acid (“NDA”), 6-hydroxy-2-naphthoic acid(“HNA”), or combinations thereof. That is, the total amount of repeatingunits derived from naphthenic hydroxycarboxylic and/or dicarboxylicacids (e.g., NDA, HNA, or a combination of HNA and NDA) is typicallyabout 15 mol. % or less, in some embodiments about 10 mol. % or less,and in some embodiments, from about 1 mol. % to about 8 mol. % of thepolymer.

B. Electrically Conductive Filler

As indicated above, an electrically conductive filler is also employedin the polymer composition to achieve the desired surface and/or volumeresistivity values. This may be accomplished by selecting a singlematerial for the filler having the desired resistivity, or by blendingmultiple materials together (e.g., insulative and electricallyconductive) so that the resulting filler has the desired resistivity. Inone particular embodiment, for example, an electrically conductivematerial may be employed that has a volume resistivity of less thanabout 1 ohm-cm, in some embodiments about less than about 0.1 ohm-cm,and in some embodiments, from about 1×10⁻⁸ to about 1×10⁻² ohm-cm lessthan about 0.1 ohm-cm, and in some embodiments, from about 1×10⁻⁸ toabout 1×10⁻² ohm-cm, such as determined at a temperature of about 20° C.in accordance with ASTM D257-14 (technically equivalent to IEC62631-3-1). Suitable electrically conductive materials may include, forinstance, carbon materials, such as graphite, carbon black, carbonfibers, graphene, carbon nanotubes, etc. Other suitable electricallyconductive fillers may likewise include metals (e.g., metal particles,metal flakes, metal fibers, etc.), ionic liquids, and so forth.Regardless of the materials employed, the electrically conductive fillertypically constitutes from about 0.5 to about 20 parts, in someembodiments from about 1 to about 15 parts, and in some embodiments,from about 2 to about 8 parts by weight per 100 parts by weight of thepolymer matrix. For example, the electrically conductive filler mayconstitute from about 0.1 wt. % to about 10 wt. %, in some embodimentsfrom about 0.2 wt. % to about 8 wt. %, and in some embodiments, fromabout 0.5 wt. % to about 4 wt. % of the polymer composition.

C. Mineral Filler

If desired, the polymer composition may also contain one or more mineralfillers distributed within the polymer matrix. Such mineral fillerstypically constitute from about 10 to about 80 parts, in someembodiments from about 20 to about 70 parts, and in some embodiments,from about 30 to about 60 parts per 100 parts by weight of the polymermatrix. The mineral filler may, for instance, constitute from about 5wt. % to about 60 wt. %, in some embodiments from about 10 wt. % toabout 55 wt. %, and in some embodiments, from about 25 wt. % to about 40wt. % of the polymer composition. Further, the weight ratio of themineral filler to the electrically conductive filler may range fromabout 2 to about 500, in some embodiments from about 3 to about 150, insome embodiments from about 4 to about 75, and in some embodiments, fromabout 5 to about 15. By selectively tailoring the type and relativeamount of the mineral filler, the present inventor has not onlydiscovered that the mechanical properties can be improved, but also thatthe thermal conductivity can be increased without significantlyimpacting the overall electrical conductivity of the polymercomposition. This allows the composition to be capable of creating athermal pathway for heat transfer away from the resulting electronicdevice so that “hot spots” can be quickly eliminated and the overalltemperature can be lowered during use. The composition may, for example,exhibit an in-plane thermal conductivity of about 0.2 W/m-K or more, insome embodiments about 0.5 W/m-K or more, in some embodiments about 0.6W/m-K or more, in some embodiments about 0.8 W/m-K or more, and in someembodiments, from about 1 to about 3.5 W/m-K, as determined inaccordance with ASTM E 1461-13. The composition may also exhibit athrough-plane thermal conductivity of about 0.3 W/m-K or more, in someembodiments about 0.5 W/m-K or more, in some embodiments about 0.40W/m-K or more, and in some embodiments, from about 0.7 to about 2 W/m-K,as determined in accordance with ASTM E 1461-13. Notably, it has beendiscovered that such a thermal conductivity can be achieved without useof conventional materials having a high degree of intrinsic thermalconductivity. For example, the polymer composition may be generally freeof fillers having an intrinsic thermal conductivity of 50 W/m-K or more,in some embodiments 100 W/m-K or more, and in some embodiments, 150W/m-K or more. Examples of such high intrinsic thermally conductivematerials may include, for instance, boron nitride, aluminum nitride,magnesium silicon nitride, graphite (e.g., expanded graphite), siliconcarbide, carbon nanotubes, zinc oxide, magnesium oxide, beryllium oxide,zirconium oxide, yttrium oxide, aluminum powder, and copper powder.While it is normally desired to minimize the presence of such highintrinsic thermally conductive materials, they may nevertheless bepresent in a relatively small percentage in certain embodiments, such asin an amount of about 10 wt. % or less, in some embodiments about 5 wt.% or less, and in some embodiments, from about 0.01 wt. % to about 2 wt.% of the polymer composition.

The nature of the mineral filler employed in the polymer composition mayvary, such as mineral particles, mineral fibers (or “whiskers”), etc.,as well as blends thereof. Suitable mineral fibers may, for instance,include those that are derived from silicates, such as neosilicates,sorosilicates, inosilicates (e.g., calcium inosilicates, such aswollastonite; calcium magnesium inosilicates, such as tremolite; calciummagnesium iron inosilicates, such as actinolite; magnesium ironinosilicates, such as anthophyllite; etc.), phyllosilicates (e.g.,aluminum phyllosilicates, such as palygorskite), tectosilicates, etc.;sulfates, such as calcium sulfates (e.g., dehydrated or anhydrousgypsum); mineral wools (e.g., rock or slag wool); and so forth.Particularly suitable are inosilicates, such as wollastonite fibersavailable from Nyco Minerals under the trade designation NYGLOS® (e.g.,NYGLOS® 4W or NYGLOS® 8). The mineral fibers may have a median diameterof from about 1 to about 35 micrometers, in some embodiments from about2 to about 20 micrometers, in some embodiments from about 3 to about 15micrometers, and in some embodiments, from about 7 to about 12micrometers. The mineral fibers may also have a narrow sizedistribution. That is, at least about 60% by volume of the fibers, insome embodiments at least about 70% by volume of the fibers, and in someembodiments, at least about 80% by volume of the fibers may have a sizewithin the ranges noted above. Without intending to be limited bytheory, it is believed that mineral fibers having the sizecharacteristics noted above can more readily move through moldingequipment, which enhances the distribution within the polymer matrix andminimizes the creation of surface defects. In addition to possessing thesize characteristics noted above, the mineral fibers may also have arelatively high aspect ratio (average length divided by median diameter)to help further improve the mechanical properties and surface quality ofthe resulting polymer composition. For example, the mineral fibers mayhave an aspect ratio of from about 2 to about 100, in some embodimentsfrom about 2 to about 50, in some embodiments from about 3 to about 20,and in some embodiments, from about 4 to about 15. The volume averagelength of such mineral fibers may, for example, range from about 1 toabout 200 micrometers, in some embodiments from about 2 to about 150micrometers, in some embodiments from about 5 to about 100 micrometers,and in some embodiments, from about 10 to about 50 micrometers.

Other suitable mineral fillers are mineral particles. The averagediameter of the particles may, for example, range from about 5micrometers to about 200 micrometers, in some embodiments from about 8micrometers to about 150 micrometers, and in some embodiments, fromabout 10 micrometers to about 100 micrometers. The shape of theparticles may vary as desired, such as granular, flake-shaped, etc.Flake-shaped particles, for instance, may be employed that have arelatively high aspect ratio (e.g., average diameter divided by averagethickness), such as about 4 or more, in some embodiments about 8 ormore, and in some embodiments, from about 10 to about 500. The averagethickness of such flake-shaped particles may likewise be about 2micrometers or less, in some embodiments from about 5 nanometers toabout 1 micrometer, and in some embodiments, from about 20 nanometers toabout 500 nanometers. Regardless of their shape and size, the particlesare typically formed from a natural and/or synthetic silicate mineral,such as talc, mica, halloysite, kaolinite, illite, montmorillonite,vermiculite, palygorskite, pyrophyllite, calcium silicate, aluminumsilicate, wollastonite, etc. Talc and mica are particularly suitable.Any form of mica may generally be employed, including, for instance,muscovite (KAl₂(AlSi₃)O₁₀(OH)₂), biotite (K(Mg,Fe)₃(AlSi₃)O₁₀(OH)₂),phlogopite (KMg₃(AlSi₃)O₁₀(OH)₂), lepidolite(K(Li,Al)₂₋₃(AlSi₃)O₁₀(OH)₂), glauconite(K,Na)(Al,Mg,Fe)₂(Si,Al)₄O₁₀(OH)₂), etc. Muscovite-based mica isparticularly suitable for use in the polymer composition.

D. Optional Components

A wide variety of additional additives can also be included in thepolymer composition, such as glass fibers, impact modifiers, lubricants,pigments (e.g. carbon black), antioxidants, stabilizers, surfactants,waxes, flame retardants, anti-drip additives, nucleating agents (e.g.,boron nitride) and other materials added to enhance properties andprocessability. Lubricants, for example, may be employed in the polymercomposition in an amount from about 0.05 wt. % to about 1.5 wt. %, andin some embodiments, from about 0.1 wt. % to about 0.5 wt. % (by weight)of the polymer composition. Examples of such lubricants include fattyacids esters, the salts thereof, esters, fatty acid amides, organicphosphate esters, and hydrocarbon waxes of the type commonly used aslubricants in the processing of engineering plastic materials, includingmixtures thereof. Suitable fatty acids typically have a backbone carbonchain of from about 12 to about 60 carbon atoms, such as myristic acid,palmitic acid, stearic acid, arachic acid, montanic acid, octadecinicacid, parinric acid, and so forth. Suitable esters include fatty acidesters, fatty alcohol esters, wax esters, glycerol esters, glycol estersand complex esters. Fatty acid amides include fatty primary amides,fatty secondary amides, methylene and ethylene bisamides andalkanolamides such as, for example, palmitic acid amide, stearic acidamide, oleic acid amide, N,N′-ethylenebisstearamide and so forth. Alsosuitable are the metal salts of fatty acids such as calcium stearate,zinc stearate, magnesium stearate, and so forth; hydrocarbon waxes,including paraffin waxes, polyolefin and oxidized polyolefin waxes, andmicrocrystalline waxes. Particularly suitable lubricants are acids,salts, or amides of stearic acid, such as pentaerythritol tetrastearate,calcium stearate, or N,N′-ethylenebisstearamide. Yet another suitablelubricant may be a siloxane polymer that improves internal lubricationand that also helps to bolster the wear and friction properties of thecomposition encountering another surface. Such siloxane polymerstypically constitute from about 0.2 to about 20 parts, in someembodiments from about 0.5 to about 10 parts, and in some embodiments,from about 0.8 to about 5 parts per 100 parts of the polymer matrixemployed in the composition. Any of a variety of siloxane polymers maygenerally be employed. The siloxane polymer may, for instance, encompassany polymer, co-polymer or oligomer that includes siloxane units in thebackbone having the formula:

R_(r)SiO_((4-r/2))

wherein

R is independently hydrogen or substituted or unsubstituted hydrocarbonradicals, and

r is 0, 1, 2 or 3.

Some examples of suitable radicals R include, for instance, alkyl, aryl,alkylaryl, alkenyl or alkynyl, or cycloalkyl groups, optionallysubstituted, and which may be interrupted by heteroatoms, i.e., maycontain heteroatom(s) in the carbon chains or rings. Suitable alkylradicals, may include, for instance, methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl andtert-pentyl radicals, hexyl radicals (e.g., n-hexyl), heptyl radicals(e.g., n-heptyl), octyl radicals (e.g., n-octyl), isooctyl radicals(e.g., 2,2,4-trimethylpentyl radical), nonyl radicals (e.g., n-nonyl),decyl radicals (e.g., n-decyl), dodecyl radicals (e.g., n-dodecyl),octadecyl radicals (e.g., n-octadecyl), and so forth. Likewise, suitablecycloalkyl radicals may include cyclopentyl, cyclohexyl cycloheptylradicals, methylcyclohexyl radicals, and so forth; suitable arylradicals may include phenyl, biphenyl, naphthyl, anthryl, andphenanthryl radicals; suitable alkylaryl radicals may include o-, m- orp-tolyl radicals, xylyl radicals, ethylphenyl radicals, and so forth;and suitable alkenyl or alkynyl radicals may include vinyl, 1-propenyl,1-butenyl, 1-pentenyl, 5-hexenyl, butadienyl, hexadienyl, cyclopentenyl,cyclopentadienyl, cyclohexenyl, ethynyl, propargyl 1-propynyl, and soforth. Examples of substituted hydrocarbon radicals are halogenatedalkyl radicals (e.g., 3-chloropropyl, 3,3,3-trifluoropropyl, andperfluorohexylethyl) and halogenated aryl radicals (e.g., p-chlorophenyland p-chlorobenzyl). In one particular embodiment, the siloxane polymerincludes alkyl radicals (e.g., methyl radicals) bonded to at least 70mol % of the Si atoms and optionally vinyl and/or phenyl radicals bondedto from 0.001 to 30 mol % of the Si atoms. The siloxane polymer is alsopreferably composed predominantly of diorganosiloxane units. The endgroups of the polyorganosiloxanes may be trialkylsiloxy groups, inparticular the trimethylsiloxy radical or the dimethylvinylsiloxyradical. However, it is also possible for one or more of these alkylgroups to have been replaced by hydroxy groups or alkoxy groups, such asmethoxy or ethoxy radicals. Particularly suitable examples of thesiloxane polymer include, for instance, dimethylpolysiloxane,phenylmethylpolysiloxane, vinylmethylpolysiloxane, andtrifluoropropylpolysiloxane.

The siloxane polymer may also include a reactive functionality on atleast a portion of the siloxane monomer units of the polymer, such asone or more of vinyl groups, hydroxyl groups, hydrides, isocyanategroups, epoxy groups, acid groups, halogen atoms, alkoxy groups (e.g.,methoxy, ethoxy and propoxy), acyloxy groups (e.g., acetoxy andoctanoyloxy), ketoximate groups (e.g., dimethylketoxime, methylketoximeand methylethylketoxime), amino groups (e.g., dimethylamino,diethylamino and butylamino), amido groups (e.g., N-methylacetamide andN-ethylacetamide), acid amido groups, amino-oxy groups, mercapto groups,alkenyloxy groups (e.g., vinyloxy, isopropenyloxy, and1-ethyl-2-methylvinyloxy), alkoxyalkoxy groups (e.g., methoxyethoxy,ethoxyethoxy and methoxypropoxy), aminoxy groups (e.g., dimethylaminoxyand diethylaminoxy), mercapto groups, etc.

Regardless of its particular structure, the siloxane polymer typicallyhas a relatively high molecular weight, which reduces the likelihoodthat it migrates or diffuses to the surface of the polymer compositionand thus further minimizes the likelihood of phase separation. Forinstance, the siloxane polymer typically has a weight average molecularweight of about 100,000 grams per mole or more, in some embodimentsabout 200,000 grams per mole or more, and in some embodiments, fromabout 500,000 grams per mole to about 2,000,000 grams per mole. Thesiloxane polymer may also have a relative high kinematic viscosity, suchas about 10,000 centistokes or more, in some embodiments about 30,000centistokes or more, and in some embodiments, from about 50,000 to about500,000 centistokes.

If desired, silica particles (e.g., fumed silica) may also be employedin combination with the siloxane polymer to help improve its ability tobe dispersed within the composition. Such silica particles may, forinstance, have a particle size of from about 5 nanometers to about 50nanometers, a surface area of from about 50 square meters per gram(m²/g) to about 600 m²/g, and/or a density of from about 160 kilogramper cubic meter (kg/m³) to about 190 kg/m³. When employed, the silicaparticles typically constitute from about 1 to about 100 parts, and insome some embodiments, from about 20 to about 60 parts by weight basedon 100 parts by weight of the siloxane polymer. In one embodiment, thesilica particles can be combined with the siloxane polymer prior toaddition of this mixture to the polymer composition. For instance, amixture including an ultrahigh molecular weight polydimethylsiloxane andfumed silica can be incorporated in the polymer composition. Such apre-formed mixture is available as Genioplast® Pellet S from WackerChemie, AG.

One benefit of the present invention is that the polymer composition canbe readily plated without the use of conventional laser activatablespinel crystals, which generally have the formula, AB₂O₄, wherein A is ametal cation having a valance of 2 (e.g., cadmium, chromium, manganese,nickel, zinc, copper, cobalt, iron, magnesium, tin, or titanium) and Bis a metal cation having a valance of 3 (e.g., chromium, iron, aluminum,nickel, manganese, or tin). Typically, A in the formula above providesthe primary cation component of a first metal oxide cluster and Bprovides the primary cation component of a second metal oxide cluster.For example, the first metal oxide cluster generally has a tetrahedralstructure and the second metal oxide duster generally has an octahedralduster. Particular examples of such spinel crystals include, forinstance, MgAl₂O₄, ZnAl₂O₄, FeA₂O₄, CuFe₂O₄, CuCr₂O₄, MnFe₂O₄, NiFe₂O₄,TiFe₂O₄, FeCr₂O₄, or MgCr₂O₄. The polymer composition may be free ofsuch spinel crystals (i.e., 0 wt. %), or such crystals may be present inonly a small concentration, such as in an amount of about 1 wt. % orless, in some embodiments about 0.5 wt. % or less, and in someembodiments, from about 0.001 wt. % to about 0.2 wt. %.

II. Formation

The components of the polymer composition (e.g., aromatic polymer(s),electrically conductive filler, mineral filler, etc.) may be meltprocessed or blended together. The components may be supplied separatelyor in combination to an extruder that includes at least one screwrotatably mounted and received within a barrel (e.g., cylindricalbarrel) and may define a feed section and a melting section locateddownstream from the feed section along the length of the screw. Theextruder may be a single screw or twin screw extruder. The speed of thescrew may be selected to achieve the desired residence time, shear rate,melt processing temperature, etc. For example, the screw speed may rangefrom about 50 to about 800 revolutions per minute (“rpm”), in someembodiments from about 70 to about 150 rpm, and in some embodiments,from about 80 to about 120 rpm. The apparent shear rate during meltblending may also range from about 100 seconds⁻¹ to about 10,000seconds⁻¹, in some embodiments from about 500 seconds⁻¹ to about 5000seconds⁻¹, and in some embodiments, from about 800 seconds⁻¹ to about1200 seconds⁻¹. The apparent shear rate is equal to 4Q/πR³, where Q isthe volumetric flow rate (“m³/s”) of the polymer melt and R is theradius (“m”) of the capillary (e.g., extruder die) through which themelted polymer flows.

Regardless of the particular manner in which it is formed, the resultingpolymer composition can possess excellent thermal properties. Forexample, the melt viscosity of the polymer composition may be low enoughso that it can readily flow into the cavity of a mold having smalldimensions. In one particular embodiment, the polymer composition mayhave a melt viscosity of from about 10 to about 250 Pa-s, in someembodiments from about 15 to about 200 Pa-s, in some embodiments fromabout 20 to about 150 Pa-s, and in some embodiments, from about 30 toabout 100 Pa-s, determined at a shear rate of 1,000 seconds⁻¹. Meltviscosity may be determined in accordance with ISO Test No. 11443:2014at a temperature that is 15° C. higher than the melting temperature ofthe composition (e.g., about 340° C. for a melting temperature of about325° C.).

III. Electronic Device

As indicated above, the polymer composition is particularly well suitedfor use in an electronic device substrate on which conductive circuittraces are disposed. In certain embodiments, for example, the substratecan be molded onto a singulated carrier portion. As used herein, theterm “singulated” generally means that the carrier portion has beenseparated from a larger carrier (e.g., conjoined or continuous). Thesubstrate may be formed using a variety of different techniques.Suitable techniques may include, for instance, injection molding,low-pressure injection molding, extrusion compression molding, gasinjection molding, foam injection molding, low-pressure gas injectionmolding, low-pressure foam injection molding, gas extrusion compressionmolding, foam extrusion compression molding, extrusion molding, foamextrusion molding, compression molding, foam compression molding, gascompression molding, etc. For example, an injection molding system maybe employed that includes a mold within which the polymer compositionmay be injected. The time inside the injector may be controlled andoptimized so that polymer matrix is not pre-solidified. When the cycletime is reached and the barrel is full for discharge, a piston may beused to inject the composition to the mold cavity. Compression moldingsystems may also be employed. As with injection molding, the shaping ofthe polymer composition into the desired article also occurs within amold. The composition may be placed into the compression mold using anyknown technique, such as by being picked up by an automated robot arm.The temperature of the mold may be maintained at or above thesolidification temperature of the polymer matrix for a desired timeperiod to allow for solidification. The molded product may then besolidified by bringing it to a temperature below that of the meltingtemperature. The resulting product may be de-molded. The cycle time foreach molding process may be adjusted to suit the polymer matrix, toachieve sufficient bonding, and to enhance overall process productivity.

A flow diagram for an embodiment a manufacturing process that can beemployed to form an electronic device is shown in FIG. 1. As shown inStep 1, a carrier 40 is provided that contains an outer region fromwhich arms 56 extend to form a leadframe 54. As shown in FIG. 4, thecarrier 40 may, for example, be unspooled from a bulk source reel 68 aand then collected in a second reel 68 b. The carrier 40 is typicallyformed from a metal (e.g., copper or copper alloy) or other suitableconductive material. If desired, the arms 56 may also contain apertures58 provided therein. Carrier holes 52 may likewise located on the outerportions of the carrier 40 to allow it to traverse along a manufacturingline in a continuous manner. In Step 2, a substrate 42, which may beformed from the polymer composition of the present invention, maythereafter be molded (e.g., overmolded) over the leadframe 54. Apertures60 may be provided in the substrate 42 that correspond to the apertures58 in the fingers 56.

Once the substrate 42 is molded over the leadframe 54, conductivecircuit traces may then be formed. Such traces may be formed through avariety of known metal deposition techniques, such as by plating (e.g.,electroplating, electroless plating, etc.), printing (e.g., digitalprinting, aerosol jet printing, etc.), and so forth. If desired, a seedlayer may initially be formed on the substrate to facilitate the metaldeposition process. In Steps 3 and 3A of FIG. 1, for instance, a seedlayer 44 may initially be deposited on the surface of the substrate 42,which allows an internal bus bar 43 formed by the carrier 40 to beelectrically connected to the seed layer 44. The seed layer 44 may thenbe deposited with a metal (e.g., copper, nickel, gold, silver, tin,lead, palladium, etc.) to form a part 46 containing electronic circuittraces 62 (Step 4). In one embodiment, for instance, electroplating maybe performed by applying a voltage potential to the carrier 40 andthereafter placed in an an electroplating bath. Vias can also beoptionally molded into the surface of the substrate to create anelectrical path between the traces and the internal layers of thecircuit. These traces create an “electrical bus bar” to the carrierportion, which enables the traces to be deposited after the depositedconductive paste is applied. If desired, the surface of the substratemay be roughened prior to being plated using a variety of knowntechniques, such as laser ablation, plasma etching, ultraviolet lighttreatment, fluorination, etc. Among other things, such roughening helpsfacilitating plating in the desired interconnect pattern. Referring toFIG. 5, for example, one embodiment of a process that employs a laserfor this purpose is illustrated in more detail. More particularly, asshown in Step 9, a laser 70 may be initially employed to ablate thesurface of the substrate 42 to create a channel 72 that forms aninterconnect pattern 66. In Step 10, an electrically conductive paste 74may then be disposed within the channel 72 via any known technique, suchas by an inkjet process, aerosol process, or screening process.Alternatively, a plating process (e.g., electroless plating) may also beemployed in lieu of and/or in addition to the use of a paste. Whenemployed, however, the deposited paste 74 may optionally be sinteredthrough a laser or flash heat 76 as illustrated in Step 11 to helpensure that the paste 74 sufficiently adheres to the substrate 42. Onceoptionally sintered, the paste 74 is then plated (e.g., electroplated)as shown in Step 12 to form electronic circuit traces 62.

Referring again to FIG. 1, once plated, an electrical device may beformed by connecting one or more electrical components 50 to thesubstrate 42 (Step 6) using any of a variety of techniques, such assoldering, wire bonding, etc. In certain embodiments, a solder mask 48may optionally be applied (Step 5) prior to the connection of thecomponents 50. The resulting electronic device may then be separatedfrom the carrier 40. FIGS. 2-3, for instance, illustrate one embodimentof an electronic device 22 during various stages of its formation. AtStep A, for instance, the carrier 40 is shown prior to molding. Step Bshows the substrate 42 after it has been molded onto the carrier portion40 and applied with electronic circuit traces 62. At Steps C and D,optional pin contacts and circuit metallization may be added to form thecompleted electronic device (Step E). The completed electronic device 22may then be separated from the adjoined carrier 40 as illustrated inFIG. 3 to form an electronic device 22 containing a singulated carrierportion 40. The resulting electronic device may contain various types ofelectronic components, such as a housing for a light source (e.g., lightemitting diode (“LED”)) for a light a tunnel light, headlamp, etc., orother electronic equipment, such as used in computers, phones,electronic control units, etc. Such products may be particularly usefulin vehicles (e.g., automobiles, buses, motorcycles, boats, etc.), suchas an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-inhybrid electric vehicle (PHEV), or other type of vehicle using electricpower for propulsion (collectively referred to as “electric vehicles”).

Referring to FIGS. 7-8, for example, one embodiment an electronicproduct is shown that is in the form of a light 20 for use in automotiveproducts. The light 20 includes a housing 24, an electronic device 22(see also FIG. 2), and a light pipe 28. The housing 24 may be formed intwo parts 24 a and 24 b as shown in FIG. 8. The housing 24 has a wall 32forming a passageway 34 therethrough and an aperture 36 that extendsthrough the wall 32 and is in communication with the passageway 34. Theaperture 36 may be transverse to the passageway 34. The electronicdevice 22 may be mounted within the passageway 34 of the housing 30. Thelight pipe 28 extends through the aperture 36 in the housing 30 and ismounted above a light emitting diode (LED) 38, which is formed as one ormore of the electronic components 50 of the electronic device 22 asdescribed herein. FIG. 6 provides a representative process for formingthe light 20. Steps 7 and 8, for instance, show that the electronicdevice 22 is singulated from the other devices and assembled with thehousing 24 and light pipe 28. After the device 22 is formed, it ismounted within the passageway 34 and the parts 24 a and 24 b of thehousing 24 are assembled together. The pin contacts 64 remain exposed.The light pipe 28 is mounted through the aperture 36 in the housing 24and is provided above the LED(s) 38.

The present invention may be better understood with reference to thefollowing examples.

Test Methods

Melt Viscosity:

The melt viscosity (Pa-s) may be determined in accordance with ISO TestNo. 11443:2014 at a shear rate of 1,000 s- and temperature 15° C. abovethe melting temperature using a Dynisco LCR7001 capillary rheometer. Therheometer orifice (die) had a diameter of 1 mm, length of 20 mm, LIDratio of 20.1, and an entrance angle of 180°. The diameter of the barrelwas 9.55 mm+0.005 mm and the length of the rod was 233.4 mm.

Melting Temperature:

The melting temperature (“Tm”) may be determined by differentialscanning calorimetry (“DSC”) as is known in the art. The meltingtemperature is the differential scanning calorimetry (DSC) peak melttemperature as determined by ISO Test No. 11357-2:2018. Under the DSCprocedure, samples were heated and cooled at 20° C. per minute as statedin ISO Standard 10350 using DSC measurements conducted on a TA Q2000Instrument.

Deflection Temperature Under Load (“DTUL”):

The deflection under load temperature may be determined in accordancewith ISO Test No. 75-2:2013 (technically equivalent to ASTM D648). Moreparticularly, a test strip sample having a length of 80 mm, thickness of10 mm, and width of 4 mm may be subjected to an edgewise three-pointbending test in which the specified load (maximum outer fibers stress)was 1.8 Megapascals. The specimen may be lowered into a silicone oilbath where the temperature is raised at 2° C. per minute until itdeflects 0.25 mm (0.32 mm for ISO Test No. 75-2:2013).

Tensile Modulus, Tensile Stress, and Tensile Elongation:

Tensile properties may be tested according to ISO Test No. 527:2019(technically equivalent to ASTM D638). Modulus and strength measurementsmay be made on the same test strip sample having a length of 80 mm,thickness of 10 mm, and width of 4 mm. The testing temperature may be23° C., and the testing speeds may be 1 or 5 mm/min.

Flexural Modulus, Flexural Stress, and Flexural Elongation:

Flexural properties may be tested according to ISO Test No. 178:2019(technically equivalent to ASTM D790). This test may be performed on a64 mm support span. Tests may be run on the center portions of uncut ISO3167 multi-purpose bars. The testing temperature may be 23° C. and thetesting speed may be 2 mm/min.

Unnotched and Notched Charpy Impact Strength:

Charpy properties may be tested according to ISO Test No. ISO179-1:2010) (technically equivalent to ASTM D256-10, Method B). Thistest may be run using a Type 1 specimen size (length of 80 mm, width of10 mm, and thickness of 4 mm). When testing the notched impact strength,the notch may be a Type A notch (0.25 mm base radius). Specimens may becut from the center of a multi-purpose bar using a single tooth millingmachine. The testing temperature may be 23° C.

Dielectric Constant (“Dk”) and Dissipation Factor (“Df”):

The dielectric constant (or relative static permittivity) anddissipation factor are determined using a known split-post dielectricresonator technique, such as described in Baker-Jarvis, et al., IEEETrans. on Dielectric and Electrical Insulation, 5(4), p. 571 (1998) andKrupka, et al., Proc. 7^(th) International Conference on DielectricMaterials: Measurements and Applications, IEEE Conference PublicationNo. 430 (September 1996). More particularly, a plaque sample having asize of 80 mm×90 mm×3 mm was inserted between two fixed dielectricresonators. The resonator measured the permittivity component in theplane of the specimen. Five (5) samples are tested and the average valueis recorded. The split-post resonator can be used to make dielectricmeasurements in the low gigahertz region, such as 1 GHz from 2 GHz.

Heat Cycle Test:

Specimens are placed in a temperature control chamber and heated/cooledwithin a temperature range of from −30° C. and 100° C. Initially, thesamples are heated until reaching a temperature of 100° C., when theywere immediately cooled. When the temperature reaches −30° C., thespecimens are immediately heated again until reaching 100° C. Twentythree (23) heating/cooling cycles may be performed over a 3-hour timeperiod.

Surface/Volume Resistivity:

The surface and volume resistivity values may be determined inaccordance with IEC 62631-3-1:2016 or ASTM D257-14. According to thisprocedure, a standard specimen (e.g., 1 meter cube) is placed betweentwo electrodes. A voltage is applied for sixty (60) seconds and theresistance is measured. The surface resistivity is the quotient of thepotential gradient (in V/m) and the current per unit of electrode length(in A/m), and generally represents the resistance to leakage currentalong the surface of an insulating material. Because the four (4) endsof the electrodes define a square, the lengths in the quotient canceland surface resistivities are reported in ohms, although it is alsocommon to see the more descriptive unit of ohms per square. Volumeresistivity is also determined as the ratio of the potential gradientparallel to the current in a material to the current density. In SIunits, volume resistivity is numerically equal to the direct-currentresistance between opposite faces of a one-meter cube of the material(ohm-m or ohm-cm).

Example 1

Samples 1-4 are formed from various percentages of a liquid crystallinepolymer (“LCP 1” and “LCP 2”), wollastonite fibers (Nyglos™ 8), carbonblack pigment, carbon fibers, and a lubricant (Glycolube™ P). LCP 1 isformed from 60 mol. % HBA, 5 mol. % HNA, 12 mol. % BP, 17.5 mol. % TA,and 5 mol. % APAP. LCP 2 is formed from 73 mol. % HBA and 27 mol. % HNA.Compounding was performed using an 18-mm single screw extruder. Partsare injection molded the samples into plaques (60 mm×60 mm).

TABLE 1 Sample 1 2 3 4 LCP 1 37.2 47.2 57.2 62.2 LCP 2 21.0 14.0 7.0 3.5Wollastonite Fibers 30 30 30 30 Carbon Black Pigment 2.5 2.5 2.5 2.5Carbon Fibers 9.0 6.0 3.0 1.5 Lubricant 0.3 0.3 0.3 0.3

Samples 1-4 were tested for thermal and mechanical properties. Theresults are set forth below in Table 2.

TABLE 2 Sample 1 2 3 4 Surface Resistivity (ohm) 4.20E+15 7.30E+151.40E+16 6.40E+15 Volume Resistivity (ohm-m) 5.00E+13 1.60E+14 1.20E+149.30E+13 Dielectric Constant (2 GHz) — — 13.1 12.5 Dissipation Factor (2GHz) — — 0.0170 0.0176 Notched Charpy (kJ/m²) 7.1 6.7 7.6 8.1 UnnotchedCharpy (kJ/m²) 11 18 34 28 Tensile Strength (MPa) 124 127 133 134Tensile Modulus (MPa) 18,916 16,690 13,067 14,278 Tensile Elongation (%)1.29 1.5 2.12 1.9 Flexural Strength (MPa) 177 179 166 171 FlexuralModulus (MPa) 18,466 16,180 13,364 14,466 Flexural Elongation (%) 1.591.77 2.54 2.21 Melt Viscosity (Pa-s) at 1,000 s⁻¹ 38.3 42.3 40.3 41.8Melting Temperature (° C., 1^(st) heat of DSC) 319.15 317.2 328.11325.28 DTUL (1.8 MPa, ° C.) 235 231 234 233

Samples 3-4 were also subjected to a heat cycle test as described above.Upon testing, it was determined that the resulting dissipation factorfor the samples was 0.021 and 0.015, respectively. Thus, the ratio ofthe dissipation factor after heat cycle testing to the initialdissipation factor for Samples 3 and 4 was 1.24 and 0.86, respectively.Upon testing, it was also determined that the resulting dielectricconstant for the samples was 12.9 and 12.6, respectively. Thus, theratio of the dielectric constant after heat cycle testing to the initialdielectric constant for Samples 3 and 4 was 0.98 and 1.01, respectively.

Example 2

Samples 5-9 are formed from various percentages of a liquid crystallinepolymer (“LCP 1” and “LCP 2”), Nyglos™ 8, carbon black pigment,graphite, and Glycolube™ P. Compounding was performed using an 18-mmsingle screw extruder. Parts are injection molded the samples intoplaques (60 mm×60 mm).

TABLE 3 Sample 1 2 3 4 LCP 1 37.2 47.2 57.2 62.2 LCP 2 22.5 15.5 7.53.75 Wollastonite Fibers 30 30 30 30 Carbon Black Pigment 2.5 2.5 2.52.5 Graphite 7.5 4.5 2.5 1.25 Lubricant 0.3 0.3 0.3 0.3

Samples 5-9 were tested for thermal and mechanical properties. Theresults are set forth below in Table 4.

TABLE 4 Sample 5 6 7 8 Surface Resistivity (ohm) 4.10E+16 2.80E+171.40E+16 3.50E+16 Volume Resistivity (ohm-m) 1.10E+14 3.50E+14 2.30E+147.80E+13 Dielectric Constant (2 GHz) 12.6 8.8 6.3 — Dissipation Factor(2 GHz) 0.0492 0.0201 0.009 — Notched Charpy (kJ/m²) 4.3 5.3 7.8 12.6Unnotched Charpy (kJ/m²) 26 30 43 50 Tensile Strength (MPa) 109 132 139130 Tensile Modulus (MPa) 13491 14737 14562 14229 Tensile Elongation (%)1.53 1.68 1.96 1.79 Flexural Strength (MPa) 144 167 177 176 FlexuralModulus (MPa) 13689 13858 14259 14091 Flexural Elongation (%) 1.7 2.42.54 2.47 Melt Viscosity (Pa-s) at 1,000 s⁻¹ 46.7 45.5 43.5 39.4 MeltingTemperature (° C., 1^(st) heat of DSC) 329.28 327.96 330.63 329.94 DTUL(1.8 MPa, ° C.) 221 228 234 239

Samples 5-7 were also subjected to a heat cycle test as described above.Upon testing, it was determined that the resulting dissipation factorfor the samples was 0.0578, 0.0214, and 0.0098, respectively. Thus, theratio of the dissipation factor after heat cycle testing to the initialdissipation factor for Samples 5, 6, and 7 was 1.17, 1.06, and 1.09,respectively. Upon testing, it was also determined that the resultingdielectric constant for the samples was 12.6, 8.9, and 6.3,respectively. Thus, the ratio of the dielectric constant after heatcycle testing to the initial dielectric constant for Samples 5, 6, and 7was 1.0, 1.0, and, 1.0, respectively.

These and other modifications and variations of the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention. Inaddition, it should be understood that aspects of the variousembodiments may be interchanged both in whole or in part. Furthermore,those of ordinary skill in the art will appreciate that the foregoingdescription is by way of example only, and is not intended to limit theinvention so further described in such appended claims.

What is claimed is:
 1. A polymer composition for use in an electronicdevice, wherein the polymer composition comprises a liquid crystallinepolymer, an electrically conductive filler, and a mineral filler, andfurther wherein the polymer composition exhibits a surface resistivityof from about 1×10¹² ohms to about 1×10¹⁶ ohms as determined inaccordance with ASTM D257-14.
 2. The polymer composition of claim 1,wherein the polymer composition exhibits a volume resistivity of 1×10¹⁰ohm-m to about 1×10¹⁶ ohm-m as determined in accordance with ASTMD257-14.
 3. The polymer composition of claim 1, wherein the polymermatrix constitutes from about 30 wt. % to about 80 wt. % of the polymercomposition.
 4. The polymer composition of claim 1, wherein the liquidcrystalline polymer contains one or more repeating units derived from anaromatic hydroxycarboxylic acid, wherein the hydroxycarboxylic acidrepeating units constitute about 40 mol. % or more of the polymer. 5.The polymer composition of claim 4, wherein the liquid crystallinepolymer contains repeating units derived from 4-hydroxybenzoic acid,6-hydroxy-2-naphthoic acid, or a combination thereof.
 6. The polymercomposition of claim 4, wherein the liquid crystalline polymer containsrepeating units derived from 4-hydroxybenzoic acid in an amount of fromabout 30 mol. % to about 90 mol. % of the polymer and contains repeatingunits derived from 6-hydroxy-2-naphthoic acid in amount of from about 1mol. % to about 30 mol. % of the polymer.
 7. The polymer composition ofclaim 4, wherein the liquid crystalline polymer further containsrepeating units derived from terephthalic acid, isophthalic acid,2,6-naphthalenedicarboxylic acid, hydroquinone, 4,4′-biphenol,acetaminophen, 4-aminophenol, or a combination thereof.
 8. The polymercomposition of claim 1, wherein the electrically conductive fillerincludes a carbon material.
 9. The polymer composition of claim 8,wherein the carbon material has a volume resistivity of less than about1 ohm-cm.
 10. The polymer composition of claim 8, wherein the carbonmaterial includes graphite, carbon black, carbon fibers, graphene,carbon nanotubes, or a combination thereof.
 11. The polymer compositionof claim 1, wherein the electrically conductive filler is present in thepolymer composition in an amount of from about 0.5 to about 20 parts byweight per 100 parts by weight of the polymer matrix.
 12. The polymercomposition of claim 1, wherein the mineral filler is present in thepolymer composition in an amount of from about 10 to about 80 parts byweight per 100 parts by weight of the polymer matrix.
 13. The polymercomposition of claim 12, wherein the weight ratio of the mineral fillerto the electrically conductive filler ranges from about 2 to about 500.14. The polymer composition of claim 12, wherein the mineral fillercontains mineral particles, mineral fibers, or a combination thereof.15. The polymer composition of claim 14, wherein the mineral particlesinclude talc, mica, or a combination thereof.
 16. The polymercomposition of claim 14, wherein the mineral fibers includewollastonite.
 17. The polymer composition of claim 14, wherein themineral fibers have a median diameter of from about 1 to about 35micrometers.
 18. The polymer composition of claim 14, wherein themineral fibers have an aspect ratio of from about 1 to about
 50. 19. Thepolymer composition of claim 1, wherein the polymer composition has amelt viscosity of from about 10 to about 250 Pa-s, as determined inaccordance with ISO Test No. 11443:2014 at a shear rate of 1,000 s- andtemperature that is 15° C. above the melting temperature of thecomposition.
 20. The polymer composition of claim 1, wherein the polymercomposition exhibits a dielectric constant of about 4 or more and adissipation factor of about 0.3 or less, as determined at a frequency of2 GHz.
 21. The polymer composition of claim 20, wherein the compositionexhibits a dielectric constant after being exposed to a temperaturecycle of from about −30° C. to about 100° C., wherein the ratio of thedielectric constant after the temperature cycle to the dielectricconstant prior to the heat cycle is about 0.8 or more.
 22. The polymercomposition of claim 20, wherein the composition exhibits a dissipationfactor after being exposed to a temperature cycle of from about −30° C.to about 100° C., wherein the ratio of the dissipation factor after thetemperature cycle to the dissipation factor prior to the heat cycle isabout 1.3 or less.
 23. The polymer composition of claim 1, wherein thepolymer composition is free of spinel crystals.
 24. A substratecomprising the polymer composition of claim 1, wherein conductivecircuit traces are disposed on a surface of the substrate.
 25. Anelectronic device comprising the substrate of claim 24, wherein thesubstrate is molded onto a singulated carrier portion.
 26. Theelectronic device of claim 24, wherein the singulated carrier portioncomprises a metal.
 27. The electronic device of claim 24, wherein thesubstrate contains a channel within which a seed layer is disposed, andfurther wherein the circuit traces are disposed on the seed layer. 28.The electronic device of claim 27, wherein the channel is formed by alaser.